CONOP3(3NCARG)

📦 version 6.6.2, in epel 9, fedora 43, fedora 44

✨ CONOP3 ✨

okay so bestie, this is CONOP3 from the NCAR GRAPHICS manual (3NCARG section, iykyk) — it's the little subroutine that flips all the switches and drops all the REAL numbers into the Conran_family utility before you actually go make a contour plot. it's giving backstage crew. it's giving setting-the-vibe-before-the-main-character-arrives. 💅

NAME 🎀

CONOP3 — sets option switches and specifys various REAL parameters to be used by the Conran_family utility.

yes bestie, "specifys" — that's literally what the original says and we do not correct our elders 💖

SYNOPSIS 🌸

CALL CONOP3 (IOPT, ARRAY, LENA)

DESCRIPTION 🦋

okay so here's the whole cast of characters:

  • IOPT — Character, input 💜 — this one picks an internal parameter and sets an option switch. The possibilities are literally:
'CHL=ON' or 'CHL=OFF'
'CIL=ON' or 'CIL=OFF'
'CON=ON' or 'CON=OFF'
'DBP=ON' or 'DBP=OFF'
'SDC=ON' or 'SDC=OFF'
'SLD=ON' or 'SLD=OFF'
'TEN=ON' or 'TEN=OFF'
  • ARRAY — Real array, input ✨ — sets an internal parameter.
  • LENA — Integer, input 🍓 — the length of array ARRAY.

so here's the tea on how this works, and it's actually so simple once it clicks:

  • If an option is turned 'ON', then the remaining CONOP3 arguments can be used to override the default settings of that option.
  • If the option is 'OFF', then the remaining arguments of the CONOP3 call can be any dummy values you want, bestie, go feral. Option settings will be returned to their default values.

The following options are defined by this subroutine — buckle up, there's seven of them and they all ate:

CHL 👑

This parameter determines how the high and low contour values are set. These contour values may be set by the program or by the user.

  • If CHL=OFF, the program examines the user's input data and determines both the high and low values.
  • If CHL=ON, the user must specify the desired high (HI) and low (FLO) values.
  • The default is CHL=OFF.
If program set: CALL CONOP3('CHL=OFF',0.,0)

If user set: CALL CONOP3('CHL=ON',ARRAY,2) where ARRAY(1)=HI,
ARRAY(2)=FLO
Note: The values supplied for contour increment and contour high and low values assume unscaled data values. See the SDC parameter, below. 👀

CIL 💖

This parameter determines how the contour increment (CINC) is set. The increment is either calculated by the program (CIL=OFF) using the range of high and low values from the user's input data, or set by the user (CIL=ON). The default is CIL=OFF.

If program set: CALL CONOP3('CIL=OFF',0.,0)

If user set:  CALL CONOP3('CIL=ON',CINC,1)
Note: By default, ('CIL=OFF') the program will examine the user's input data and determine the contour interval (CINC) at some appropriate range between the level of high and low values supplied, usually generating between 15 and 20 contour levels.

Example:

CALL CONOP3('CIL=ON',10.,1)

will generate contours at increments of 10. units in user coordinates. slay. 🔥

CON 🌈

This parameter determines how the contour levels are set.

  • If CON=ON, the user must specify an array of contour values and the number of contour levels. A maximum of NCL=30 contour levels is permitted.
  • If CON=OFF, NCL and the contour values are computed.
  • The default is OFF.
If program set: CALL CONOP3('CON=OFF',0.,0)

If user set: CALL CONOP3('CON=ON',ARRAY,NCL)
Note: The real array (ARRAY) must have the contour levels ordered from smallest to largest.
Warning: It is illegal to use the CON option when either CIL or CHL are activated. If this is done, the option call that detected the error will not be executed. no cap, do not do this bestie. 💀

DBP 🧚

This parameter determines how the dash pattern break point (BP) is set. (Does not apply to entry CONRAQ.)

  • If DBP=ON, BP must be set by the user.
  • If DBP=OFF, the program will set BP to 0. This is the default.
If program set: CALL CONOP3('DBP=OFF',0.,0)

If user set:  CALL CONOP3('DBP=ON',BP,1)
Note: BP is a floating point number where the break for GTR and LSS contour dash patterns are defined. BP is assumed to be given relative to the untransformed contours.

To see how various dash line patterns can be assigned to various contours see parameter DBP in "man conop4". 🫶

SDC ⭐

The parameter to determine how to scale the input data from which the contours are generated. (Does not apply to entry CONRAQ.)

  • If SDC=ON, the scaling factor is set to ARRAY(1).
  • If SDC=OFF, the default scale factor of 1. is used.
If program set: CALL CONOP3('SDC=OFF',0.,0)

If user set:  CALL CONOP3('SDC=ON',ARRAY,1)
Note: The data plotted on contour lines and the data plotted for relative minimums and maximums will be scaled by ARRAY.

SLD 🛡️

Input a polygon to define the extent of area to be contoured. (Does not apply to entry CONRAQ.)

When this option is activated, only those contours within the shield are drawn. The shield is a polygon specified by the user which must be given in the same coordinate range as the the data. It must define only one polygon.

To input a shield:

  CALL CONOP3('SLD=ON',ARRAY,LENA)

Otherwise:

  CALL CONOP3('SLD=OFF',0.,0)
Note: ARRAY is a real array LENA elements long. The first LENA/2 elements are X coordinates and the second LENA/2 elements are Y coordinates. This polygon must be closed, that is the first and last points in ARRAY must be the same.

Example:

 DIMENSION SHLD(10)
 DATA SHLD/ 7.,10.,10.,7.,7.,
1            7.,7.,10.,10.,7./
 CALL CONOP3 ('SLD=ON',SHLD,10)

TEN 🎀

The parameter to determine the tension factor applied when smoothing contour lines using splines under tension. (Does not apply to entry CONRAQ.)

If user set, the allowed range is from greater than zero to 30. The higher the tension the less smoothing occurs. The default value (TEN=OFF) is 2.5.

If program set: CALL CONOP3('TEN=OFF',0.,0)

If user set:  CALL CONOP3('TEN=ON',TENS,1)
Note: This option is not available in the standard version of CONRAN. 😭

USAGE 💫

CONOP3 is called to set parameters of type REAL before CONRAN, CONRAQ, or CONRAS are called to generate the contour plot. order of operations queen 👑

EXAMPLES 🔥

Use the command ncargex to see the following examples: tconaq, tconan, and tconas. go look, they're iconic.

ACCESS 🌸

To use CONOP3 load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order. (yes bestie, in that order, the linker has opinions 🫶)

MESSAGES 💌

See the conran_family man page for a description of all Conran_family error messages and/or informational messages.

SEE ALSO 🌈

Online: conran_family, conran_family_params, conran, conraq, conras, conop1, conop2, conop4, conpack, conpack_params

Hardcopy: NCAR Graphics Contouring and Mapping Tutorial; NCAR Graphics Fundamentals, UNIX Version; User's Guide for NCAR GKS-0A Graphics

Copyright (C) 1987-2009 University Corporation for Atmospheric Research

The use of this Software is governed by a License Agreement.

okay that's the whole page, bestie, you're officially fluent in CONOP3 💅✨

this was the UNIX version of the page, dated March 1993 — vintage but still serving, fr fr 🎀🦋💖

📦 where this page comes from